Post on 12-Jan-2016
description
Tobacco Production Update
Bob Pearce, Gary Palmer, Andy Bailey Extension Tobacco Specialists
Kenny SeeboldExtension Plant Pathologist
Topics
• Nitrogen sources for tobacco
• Revised nitrogen rates for tobacco
• Sucker control options– No MH options
• Variety update
• Disease update
Nitrogen Fertilizer Issues • Economics
– Leaf prices down– N fertilizer prices up
• Price tied to natural gas• Transportation costs up
• Nitrosamine concerns– Tobacco companies want less N applied
• Quality concerns– Too little: thin body, poor yield– Too much: delayed maturity, fat stems
Ammonium Nitrate Issues• Most common N source for tobacco growers• Homeland security concerns
– Can be used to make explosives– Easy availability
• Some manufacturing plants have closed– Tighter supplies– Higher costs
• Sales regulations– Permits needed to purchase large quantity?– Some dealers reluctant to stock?
Price Per Unit of Nitrogen for Selected Fertilizer Materials
0.000
0.100
0.200
0.300
0.400
0.500
0.600
Year
Pric
e (
$/l
b N
)
Anhydrous Ammonia Ammonium Nitrate Urea UAN Solutions Ammonium Sufate
Alternative N Sources• Anhydrous ammonia (82% N)
– Lowest cost per unit of N– Limited availability– Special equipment needed
• Stored as liquid under pressure• Special injectors needed• Used in illegal meth production
– Feasible only if equipment already available– Placement concerns
• Delayed uptake• Phyto-toxicity if close to plants
Alternative N Sources• Anhydrous ammonia (82% N)
– Reaction in soil• NH3 + 2O2 → H+ + NO3
- +H2O• Same lime requirement as AN
– Suggestions for use• Inject 6 to 8 inches deep• 7 to 10 days before setting
Alternative N Sources• Ammonium sulfate (21% N)
– Specialty fertilizer• Use on acid loving crops
• Use on high pH soils
– Relatively high cost per unit N– Limited availability– Soil reaction
• (NH4)2SO4 + 4O2 → 4H+ +2NO3-+ SO4
2- + 2H2O
• 3X lime requirement of AN
– Not feasible for large scale use on tobacco
Alternative N Sources• Urea (46% N)
– Intermediate cost– Handling similar to ammonium nitrate
• Can impregnate some chemicals
• Same lime requirement as AN
– Converted to nitrate in the soil• Subject to loss if surface applied
– Apply to dry soil
– Incorporate or water in
• Delayed uptake (Don’t use for sidedress)
– Feasible alternative if managed properly
Alternative N Sources• Non Pressure Solutions (28 – 32% N)
– Intermediate cost– Mixture of urea, ammonium nitrate, and water– Relatively easy to transport, store, and apply
• Most nurse tanks• Many types of sprayers
– Corrosive to equipment– Should be incorporated
– Can be used a a carrier for spray applications– Limited availability– Feasible for tobacco production
Alternative N Sources• Calcium – Ammonium Nitrate (27% N)
– Ammonium nitrate mixed with lime• 78% ammonium nitrate
– Theoretically similar to ammonium nitrate• Can impregnate some chemicals ?
– Relatively high cost?– Availability? – Limited practical experience
Alternative N Sources• Sodium Nitrate (16% N)
• Calcium Nitrate (15.5% N)
• Sodium-Potassium Nitrate (15% N)– Immediate uptake (good for sidedress)– Good for low pH soils– Erratic availability – High cost– Low analysis – high transport cost
Conversion to Nitrate in soil
% of Fertilizer as NO3-N
N Source Weeks After Application
0 3 6
Ammonium Nitrate 50 80 90
Anhydrous Ammonia 0 20 65
Urea 0 50 75
UAN Solution 25 60 80
Nitrate Sources 100 100 100
Effects of Ammonium Nitrate Application on Soil pH
5
5.2
5.4
5.6
5.8
6
6.2
6.4
1-M
ay
8-M
ay
15
-Ma
y
22
-Ma
y
29
-Ma
y
5-J
un
12
-Ju
n
19
-Ju
n
26
-Ju
n
3-J
ul
10
-Ju
l
17
-Ju
l
24
-Ju
l
31
-Ju
l
7-A
ug
14
-Au
g
21
-Au
g
Soil pH0 N 240 lbs N
Anhydrous Ammonia, Urea, UAN solutions : similar
Effect of Liming an Acid Soil Prior to Use of Urea and Sodium Nitrate Sources of Nitrogen
5.3
5.8
6.3
4.7
5.7
6
4
4.5
5
5.5
6
6.5
7
0 5 7.5
Tons of Lime/A
So
il p
H
Sodium Nitrate Urea
Both N sources applied at 225 lb N/A pre-plant. Soil pH (water) measured at midseason of each year. Soil pH before liming was 5.4.
Effect of Liming an Acid Soil Prior to Use of Urea and Sodium Nitrate Sources of Nitrogen
2612
2765 2772
2358
26472750
2000
2200
2400
2600
2800
3000
0 5 7.5Tons of Lime/A
Yie
ld l
b/a
Sodium Nitrate Urea
Both N sources applied at 225 lb N/A pre-plant.
Nitrogen Source StudyHarrison Co. – Keith Smith Farm
425 478 438 480
1040 928 1030 1039
1058 1169 1086 1007
323 313 323 342
87
187
148
68
2867287828892846 178
0
500
1000
1500
2000
2500
3000
AN U CN SN LSD
Yie
ld l
b/a
Flyings Lugs Leaf Tips Total
100 units AN Broadcast Sidedressed with 170 units each, AN = Ammonium Nitrate, U= Urea, CN = Calcium Nitrate, SN = Sodium Nitrate
Conventional Fertility TrialMonroe Co. – Al Pedigo Farm
502 532 469 498 544
829976
850 888 850
515
662657 540 544
135
241
110
1939192621691847 1977 400
0
500
1000
1500
2000
2500
450 AN +300 AN
750 AN + -
450 AN +645 CN
450 AN +625 SN
450 AN +217 U
LSD
Yie
ld l
b/a
Flyings Lugs Leaf TotalNumber = lbs of product, AN = Ammonium Nitrate, CN = Calcium Nitrate, SN = Sodium Nitrate, U= Urea
Broadcast
Sidedress
No-till Fertility TrialMonroe Co. – Al Pedigo Farm
587 750 674 577 638
10821113 1164
1062 1062
735705 817
710 725
102
181
119
24252348265425672404 295
0
500
1000
1500
2000
2500
3000
450 AN +300 AN
750 AN + -
450 AN +645 CN
450 AN +625 SN
450 AN +217 U
LSD
Yie
ld l
b/a
Flyings Lugs Leaf TotalNumber = lbs of product, AN = Ammonium Nitrate, CN = Calcium Nitrate, SN = Sodium Nitrate, U= Urea
Broadcast
Sidedress
Effects of Sidedressing Different Sources of Nitrogen on Burley Yield
Elliot Co. – Tracy D. Kitchen Farm
757 686 790 750
991815
905 873
482
442436 486
2108213019422229
0
500
1000
1500
2000
2500
300 Am Nitrate 222 Urea 645 Ca Nitrate 625 Na Nitrate
Yie
ld l
b/a
Flyings Lugs Leaf
450 Ammonium Nitrate Broadcast followed by 100 lb/a of Nitrogen Sidedressed.Am = Ammonium, Ca = Calcium & Na = Sodium. There were no significant differences.
Effect of Nitrogen Source on Burley YieldMarshall Co. – Glen Thompson Farm
373 381 377 397
1092 1048 970 1084
1176 1303 1203
57
223
1114 310
0
500
1000
1500
2000
2500
3000
Am Nitrate Urea Ca Nitrate Na Nitrate LSD
Yie
ld lb
/a
FLYINGS LUGS LEAF
2579 2605 2650 2684 225
150 units Urea Broadcast Sidedressed with 100 units each at sidedressing, Ca = Calcium and Na = Sodium
Revised Nitrogen Rates
• AGR-1 will have a new table for N on tobacco– Based on crop history (same as old)– No additional N for continuous tobacco– Soil drainage formally considered – “Typical” recommendation 50 lbs. N/A less– Rate lower if sidedressing is practiced
• Economically sound recommendations
• Reduce incidence of over-application
Revised Nitrogen Recommendations for Burley and Dark Tobacco.
Well DrainedSoil
Moderately Well Drained Soil
------------Lb N/A------------
Low N levels: following tobacco or row crops
225-250 250-275
Medium N levels: first-year tobacco following a grass or grass-legume sod
200-225 225-250
High N levels: first-year tobacco following legume sod or legume cover crop
150-175 175-200
Effects of Nitrogen Rates on Burley Tobacco at Spindletop Farm (Maury Silt Loam)
2000
2500
3000
3500
4000
0 50 100 150 200 250 300 350 400
N rate (lb/a)
Yie
ld l
b/a
1991 1992
– MacKown, Sutton and Crafts-Brander – 1994
Nrate across location years and method
y = -0.0061x2 + 4.0053x + 2180.2
R2 = 0.1249
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0 50 100 150 200 250 300 350 400
N rate (lbs./A)
Le
af
Yie
ld (
lbs
. A
)
Effect of N rate and method of application on burley tobacco yield.
2000
2250
2500
2750
3000
0 50 100 150 200 250 300 350 400
N rate (lbs/A)
Yie
ld (
lbs/
A)
Poly. (Preplant) Poly. (Split )
If 1/3 or more is sidedressed reduce total amount of N by 15 to 25 lbs./A
Summary
• Encourage growers to compare costs and consider alternative N sources
• Revised N rates – Rates lowered by about 50 lbs./A– Will not significantly lower yield– Improved quality– Promotes desired chemical properties
• Reduce rate if sidedressing is practiced